Electric-motor drive mechanism.



C. P. BANZHOF.

ELECTRIC MOTOR DRIVE MECHANISM.

APPLIUATION FILED JULY 3, 1911.

1,033,519. Patented July 23, 1912.

2 SHEETSSHEET 1.

c. P. BANZHOF.

ELECTRIC MOTOR DRIVE MECHANISM.

APPLICATION FILED JULY 3, 1911,

1,033,519. Patented July 23,1912.

2 SHEETBSHEET Z.

X Q 642k UNITED STATES P rE T orrren.

CHARLES P. BANZHOF,-"O E LANGA'ST R, PENNSYLVANIA, AssproNon TO B. GRANT STAUFFER, CHARLESIZSEAUFFER, AND LEVI w. HoR'rINe,, ALL or LANcAsI-En,

PENNSYLVANIA.

nrnernrmmo'ron DRIVE MncHANIsM.

Specification of Letters Patent.

Patented July 23, 1912.

Application filed July 3, 1911. Serial No. 636,754.

' light motor drive such as required for sewing and other light-machines.

It is to this class of electric motor drive that the present invention relates, and the object is to provide a self-contained appa ratus, the speed of which can be easily controlled within its limits, which can be brought to a quick full stop, and which can be readily applied to the machine it is in tended to operate.

Heret-ofore in the application of the light electric motor drive, especially in sewing machine use, the most common means of obtaining speed control has been by belt slip page. using a constant speed motor-.belted looselyv to the driven'pulley, with provision for tightening the belt in a varying degree. This method requires frequent belt renewals, on account of the rapidly revolving motor pulley slipping under the belt, and its proper application requires the use of a constant speed motor which for direct current must be of one design and for alternating current another design. i

In my improvement, I obtain speed coir lrol by the application of a variable brake to the motor shaft, as hereinafter described,

and I: use a motor of the series wound type,

through the well known speed charactcris tics of which the braking of the armature shaft made practical, and which by proper designing can be made to operate satisfactorily on both direct and alternating current.

In its preferred form, my improvement comprises a motor frame provided with a laminated field member, an armature journaled to revolve therein, a brake wheel or pulley fast on the armature shaft and provided with a peripheral V-groove, a wedgeshaped brake held by spring action in en gagcinent with said V-groove, and means for applying and varying the pressure of said brake in said V-groove comprising a spring-actuated operating lever fulcrumed on the motor frame and a spring-actuated brakede ver with limited motion in either direction fulcrumed on said operating lever,

together with means for opening the electric circuit before the brake is fully applied and closing the circuit after the brake is partly released.

The invention will be explained by reference to the accompanying drawings, and will be particularly pointed out in the appended claims.

Insaid drawings: Figure 1 is a front elevation of an apparatus embodying our inventio-n. Fig. 2 is a side elevation, looking at the right hand side of Fig. 1. Fig. 3 is a horizontal section of the hollow base of the motor frame showing the switch in plan, and illustrating the motor connections diagrammatically. Fig. i is a diagrammatic view illustrating the action of the mechanism in practical operation, different posi tions of the brake, levers and switch mechanism being indicated by full, dot and dotand-dash lines. Fig. 5 is a vertical section through the base of the motor frame. showing the switch mechanism in elevation.

ln the drawings, A designates the motor frame which is rigidly attached to a hollow base B..

C is the armature shaft journalcd to rcvolve in the motor frame. Fast on shaft C v is the brake wheel or pulley l) having a pcriphcral Vgroove; also a grooved pulley E for communicatingpower h bell. though of course the power llllll$llli$ ltlll may be by direct connection instead of by belt.

F is the operating instrumentality or lever which is fast to and fulcrumcd on a stud (l journalcd in the base B. t mid stud {l cxtends into the hollow hasc and is opcrativcly connected with the switch mechanism. On

the o )eratin" lever F is a rigid u iwardlv- C k v projecting arm ll carrying a stud l upon which is fulcrumed the brake-lever J. The lastnnentioncd lcvcr carries the brake K. having a segmental or arcuate wedge-shaped braking surface for engagement with the V- groove of the brake-pulley D. vSaid brake lever J is allowed a! limited movement on stud I in either direction, being so limited by contact of surfaces or stops M, and N against the operating lever F. A tension spring 0. attached tot-he brake lever and to the fulcrum end of the operating lever, tends to move the brake lever to the limit N. Surrounding stud G, with its ends attached rebase of the'mot'or frame, is astrdngerheli- "cal spring I tending by torsion-toturnstiid spectively to the operating lever and to the G in the direction indicated by"the' arrow'i in Fig.1 and thereby force the operating lever and parts carried thereby in a direction to fully apply the brake.

The normal position of the parts, when at rest, is shown by the full lines in Fig. 4. This is the ofl" position, and the electric circuit to the motor is open through the action of the switch as hereinafter described. Under influence of spring'P the operating lever F holds the stud I, on which the brake lever J is fulcrumed', in an inward osition, and -as the brake lever is restrained by engagement of brake K with pulley D, said brake lever J is held in the position shown with brake K squarely engaging the V- groove of the brake wheel or pulley and limit M in contact with F. Spring 0, which is made lighter than spring P, is held under extreme tension, and the full force of spring. P is exerted on the brake. If, now, the

operating lever F is depressed to the posi tion indicated by dotted lines in Fig. 4, the stud I constituting the fulcrum of the brake lever J will shift accordingly, but the contraction of spring O will hold the brake against the brake wheel or pulley D.' This causes the brake lever to turn on its fulcrum, clearing the limit M from contact with F;

' and the change of relative position of the brake-lever withdraws the brake K partially from the V-groove of the pulley, leaving it in engagement only at Q. If the operating lever F is further depressed, the brake lever J will continue to turn on stud I, under action of spring 0, until F engages the limit] N, when the turning movement of said brake lever will be stopped; and, if depression of'.

the operating lever be continued to the position indicated by dot-and-dash lines in Fig.

' 4, lever F -abutting against N will swing lever J outward, carrying brake K clear of pulley D as shown.

As previously noted, the end of stud G extends into the hollow base B and is operat-ively-connected with the switch mechanism. The switch is connected electrically in series with the-motor windings, and is so adjusted that it will open and remain open while the brake is under the influence of spring P.

and will close and remain closed while the.

brake is under the influence of spring 0. For this purpose I preferably employ. a

'quick-acti'n switch of the generaltype or character disclosed in U. S. Patent toI-Ior ting, No. 971,843, dated Oct-4, 1910, which is applied as follows: As represented in Figs. 3 and 5,a cam R is rigidly affixed on the stud G, and a lever S is pivoted on said stud so as to be independently movable.

Said. lever S carries in ides a spring-actuated roller T which is orced by the spring site oblique curved surfaces to. the roller.

upward throw. Said lever S also carries a flat contact plate or spring 'W, separately insulated therefrom. When the lever is thrown down, said spring W will bridge across and make. electrical connection be' tween -the separately insulated contact -springs X, which as indicated diagrammatically in Fig. 3 are connectedin series with the, series wound motor.

Referring again to the diagrammatic view in Fig. 4, it will be seen that when the brake is fully applied, the switch is open. In this position the roller T, bearing against the upper-oblique surface ofthe cam R, holds the lever Sup to a position limited by abutment of-the pin U against the motor base, with the bridging spring W clear of contact springs X asshown in full lines. The re lation of the parts is such that'when the operat-inglever F is depressed enough to .clear it from contact wlth the brake leve J at'M, the peak of the cam R' is carried past the line of motion of'the roller T in the off position, causing the roller to rol A pin 3U carried by the lever S limits its against the other or lower. oblique surface of the cam and thereby throwing down the lever S to the position indicated by dotted lines, which closes the switch by making contact between W and X. The operating" lever F may now be depress edtto the full speed positionindicated in Fig. 4 by the dot-and-dashlines without affecting the switch, as the roller T will simply ride on the lower oblique surface ofthe cam as the latter moves to thesdot and-dash line position. .If, howeveig-the operating lever is allowed to return to the 01f, position, the

opening the switch. The adjustment of the.

parts is such that in this'returnmovement ,of the camits upper oblique surfaceis presented to the roller just before the operat ing lever F abuts against the point M on the brake lever J, so that the switch opens before the brake is fully applied. Instabil- 'ity of the roller when on the peak of the cam 1 may be increased by allowing the rollercarr ing-plunger to wabble' or allowing a Islig t independent movement of the cam, or

both,fas and forthe purposes explainedcin' the. specification of the patent aforesaid.

{From the foregoingdescription, it will be seen that when theoperating lever F is de-.

pressed,brake K will be partly released, the" switch will. close, and the motor, properly connected to an electrical (circuit, W1ll'- start; though it will be restrainedfroin full,

spee'd'by the brakes As said brake whe'fl apln order to obtain the best results in my improvement, l preferably use a series wound motor proportioned as to consume practically the same electric power with the brake partly applied for minimum speed as it consumes when running at maximum speed This is readily done as in the class of drive contennilated the load increases with she speed and thus speed control by my improvement resolves itself into a shifting of power from load to the brake and rice verse; Y

The invention may be embodied in other forms than that selected for illustration, and the deta ls of ctuistruction and arrangement may be VtUlmlSl modified; hence I do not restrict myself to the specific construction herein shown and described.

I claim my invention and desire to secure by Letters Patent:

1. An electric motor drive mechanism having. in combination, a series wound motor and speed control means mounted on the motor frame crmprising a .variable brake arting on the armature shaft and an operating inatrumentality controlling the application of the brake.

2. An electric motor drive mechanism having, in combination, a series wound molor. speed control means comprising an opcrating instrumentality and a brake controlled thereby for variable application to the armature shaft, and a switch controlled by said operating instrumentality for opening the electric circuit through the motor before the brake is fully applied and for closing said cir uit when the brake is partly ltlliliiti.

3. A. drive niecl'lanism comprising an electric motor, the armature shaft of which is Pr vided with a brake wheel last thereon. an perating instrumentality. and a brake movahlv mounted on the operating instruincntalitv for Variable application to the brake wheel and controlled by said instrumentality Within the limits of its own variability; said instrumentalitv being adapted toell'ect a full release or full application of the brake.

4. A drive mechanism comprising an I electric motor, a spriogmrtnatctl brake acting on the armature shaft and arranged for ariablc application. and a springactuated operating instrumentality acting on said brake and normally holding it fully applied, said operating instruinentality adapted when displaced against the resistance of its spring to control the variable application of said brake under influence of the spring of the latter.

The combination with an electric motor, speed control means mounted on the motor frame and comprising :1 br he acting on the armature shaft and an operating instrumentality holding said brake applied and adapted to withdraw the same, said brake being capable of a limited movement relative to said operating instrumentality which movement controlled by the movement of said operating instrunn-ntality for varying the application of the brake between the limits of its full application and full release.

In con'ibination with an electric motor. speed control means comprising an operating instrun'ientalily and a brake for the armature shaft -m0vably-connected to said operating instrumentality for limited rclatire movement and controlled thereby for variable application Within certain limits and adapted to be ful applied and fully 7 released by said operating instrumcntality.

T. In combination with an electric motor, speed control means comprising an operat ing instrumcntality and a brake for the armature shaft movably-eonnected to said operating instrumentality for a limited relative movement and controlled thereby for variable application within certain limits and adapted to be fully applied and fully released h said 0 )eratin r instrumentalit Y and a switch controlled by said operating instrumentality for opening the electrical circuit through the motor before the brake is fully applied-and closing said circuit when the brake is partially released.

8. In combination with an electric motc-r,

control means comprising an operating instrumentality and a brake for the armature shaft movahly-connected to operating instrumentality lor limited relative movement and controlled thereby for variable application Within certain limits and adapted to be fully applied and fully released by said operating instrnm'entality, and a switch controlled by said operating instrumentality to close the circuit tarongh the motor when the limited free movement of said brake for releasing begins and opening said circuit at approximately the. same period of the reverse movement.

9. In combination, an electric motor and s eed control means comprising an operatiig instrumentality and a spring-actuated brake for the armature shaft carried by and having a'lurnited free movement relative to said operating inetrzmientality.

10. An electric motor having speed cm trol means comprising a spring-actuated operating instrumentality mounted on the motor frame and a brake for the armature shaft carried by and capable of a limited free motion relative to said operating instrumentality.

11. An electric motor having speed control means comprising a spring-actuated operating lever mounted on the motor frame and a spring-actuated brake for the armature shaft carried by and capable of a limited free movement relative to said operating lever.

12. In an electric motor drive mechanism, a motor frame, an armature journaled to revolve therein, a brake wheel with periplr eral V-groove fast on the armature shaft, a wedge shaped brake for engaging said V- groove, and means for applying and varying the pressure of said brake in 'said V-groove.

13. In an electric motor drive mechanism, a motor frame, an armature journaled to revolve therein, a brake wheel with peripheral V-groove fast on the armature shaft, a wedge-shaped brake for engaging said V- groove, and means for applying and varying the pressure of said brake in said V-groove comprising a springactuated operating lever mounted on the motor frame and a spring-actuated brake-applying [lever fulcrumed on said operating lever.

14:. In an electric motor drive mechanism, a motor frame, an armature journaled to revolve therein, a brake-wheel with peripheral V-groove fast on thearmature shaft, a wedge-shaped brake for engaging said V- groove, and means for applying and varying the pressure of said brake in said V- groove, comprising a spring-actuated operating lever mounted on the motor frame and a spring-actuated brake-applying lever fulcrumed on said operating lever, said brakeapplying lever having a limited movement on and relative to said operating lever.

15. In an electric motor drive mechanism, a motor frame, an armature journaled to revolve therein, a brake wheel fast on the armature shaft, a brake having a segmental or curved surface for engaging theperiphery of said brake wheel, and means for releasing said brake from one end and thereby varying its application.

16. In an electric motor drive mechanism, a motor frame, an armature journaled to revolve therein, a brake wheel fast on the armature shaft, provided with a peripheral V-groove, a brake having a segmental or curved wedge-shaped braking surface and spring-held in engagement with said V- groove, and means controlling the brake for applying and releasing 1t from one end.

17 In an electric motor drive mechanism, a motor frame, an armature journaledto revolve therein, a brake wheel fast onathe armature shaft, a brake in frictional engagement with said brake "wheel, and means for applying and varying the pressure of said a spring-aetuated brakelever with limited operating lever.

18. In an electric motor drive mechanism, a motor frame, an armature journaled to revolve therein, a brake wheel fast on the armature shaft, a brake in frictional engagement with said brake wheel, and means for applying and varying the pressure of said brake comprising a spring-actuated operating lever fulcrumed on the motor frame and a spring-actuated brake lever with limited motion in either direction fulcrumed on said operating lever, and means for opening the electric circuit before said brake is fully applied and closing said circuit after said brake is partly released. 19. In an electric motor drive mechanism, a motor frame, an armature journaled to revolve therein, a brake wheel fast on the armature shaft, a brake engaging said brake wheel, and means for applying and varying the friction of .said brake on said brake wheel comprising an operating lever fulcrumed on the motor frame and a brake lever with limited movement in either direction fulcrumed on said operating lever and cont-rolled thereby to vary the surface of contact of said brake against said brake wheel.

20. In an electric motor drive mechanism, a motor frame, an armature journaled to revolve therein, a brake wheel fast on the armature shaft, a brake engaging said brake wheel, and means for applying and. varying the riction of said brake on said brake wheel comprising an operating lever fulcrumed on the motor frame and a brake lever with limited movementin either direc tion fulcrumed on said operating lever and controlled thereby to vary the surface of contact of said brake against said brake and closing said circuit after the brake is partly released.

21. In an electric motor drive mechanism, a motor frame, an armature journaled to revolve therein. a brake wheel fast on the armature shaft, an operating lever fulcrumed on the motor frame, and a brake engaging said brake wheel and having limited movement relative to said operating lever and contact against said brake wheel.

22. In an electric motor drivelmechanism, a motor frame, an armature journalefl to revolve therein, a brake wheel fast pn the armature shaft, a brake engaging said brake wheel, means for applying and varying the action of the brake comprising a springmotion in either direction fulcrumed on said brake comprising a spring-actuated operatmg lever fulcrumedon the motor frame and ioo wheel, and means for opening theelectric circuit before said brake is fully applied controlled thereby for varying its surface of actuated operating lever and a spring-actuated brake lever with limited motlon in either direction fulcrumed on said brakelever, and switch mechanism including a peaked cam movable with said operatmg lever and a quick make-and-break lever carrying a spring-actuated roller bearing against said cam.

23. In combination, an electric motor, a brake therefor, an operating lever controlling said brake, and a switch including a peaked cam movable by said operating lever and a eo-fulcrumed quick make-andbreak lever carrying a spring-actuated roller bearing against said cam.

24. The combination of a driven wheel, a brake shoe cooperating therewith, a carrier on which said brake shoe is pivotally mounted, and a spring arranged to move said brake shoe on its pivot independently of said carrier and move its center of gravity constantly toward said driven wheel, where-* by said shoe exerts avariable and increasing pressure as it is moved b the carrier toward the wheel and a varia le and decreasing ressure as it is moved by the carrier away om said wheel.

- 25. The combination of a driven wheel, a brake applying lever, a brake shoe cooperating with the wheel and movably mounted on said lever, and a spring arranged to move said shoe independently of said lever and move its center of ravity constantly toward said driven whee whereby a variable and increasing pressure is exerted by said shoe as it is moved by the lever toward the wheel, and a variable and decreasing pressure as it is moved away from the wheel.

L1 testimony whereof I aifix my signature.

in presence of two witnesses.

Witnesses:

Enw. GERLAoH, M. C. STONER.

Copies of this patent may be obtained for five cents each, by'addressing the Commissioner of Patents. Washington, D. 0. 

